From biomass to solar to heat pumps, GMC is demonstrating how to heat our future.
Biomass Central Heat Plant
The idea started with students. In 2005, a freshman honors seminar addressing peak oil wrote a proposal for a biomass facility. They were concerned with the College burning #6 heating oil, which is one of the most carbon intensive commercial fuels.
At the time, the fossil fuels used for heat, hot water, and cooking on campus accounted for 71% of the College’s carbon footprint. Their proposal claimed that biomass consisting of locally harvested chips would be a more sustainable alternative. The Student Campus Greening Fund then funded an engineering study to see if there was a large enough supply of local woodchips to sustain the plant and whether it was a good financial investment for the College.
The study suggested it was a good investment, and newly anointed President Paul Fonteyn approved the $5.8 million project in order to take a major step toward our climate neutrality goal. The combined heat and power biomass plant officially opened on Earth Day, April 22, 2010 and now reducing oil usage by 200,000 gallons per year. The plant uses woodchips to heat over 85% of the College. The vast majority of the woodchips are harvested locally with sustainable standards, as outlined in the sustainable purchasing policy, written by students in 2014.
The chips are purchased through the Poultney Woodshed Project, which was established in 2010 as a way to directly support the local community, while allowing the College the ability to keep a close eye on the ecological impact of the fuel supply. The Poultney Woodshed Project (the “PWP”) is a partnership between Green Mountain College (GMC), the Hubbard Brook Research Foundation (HBRF), local landowners, and key stakeholders in the forest industry. It is funded by private foundations and public sources, including the Rutland Regional Planning Commission. Read the Frequently Asked Questions for more details. “This biomass plant is proof that we have the means and the technology to move towards a sustainable future,” said student Todd Martin ’10, who spoke at the ceremony. “Here in Vermont, we are grateful to have abundant forests that, if sustainably maintained and managed, can provide a renewable energy alternative to oil and coal for our electricity and heat production.”
The plant, designed and constructed by HP Cummings and local architect Smith-Alvarez-Sienkiewycz, is 400 horsepower and burns between 3,000-4,500 tons of woodchips annually. The initial investment has a payback of approximately 22 years, and for every dollar originally invested, about $1.90 will be recouped. The plant serves as an open educational laboratory for GMC students and for the general public, and a destination for people interested in learning how local, renewable resources can provide solutions to energy and environmental challenges. Tours can be arranged through the sustainability office. Click here to see a diagram of how it works!
Passive Solar Heat
Can a building heat itself? The answer is yes, especially when it is built with high insulation value, when it faces the sun, and when it has a heat slab to retain solar radiation. The Olwen Garage on the farm, built by REED students in 2014, features a passive heat design. The building has no mechanical heat source, meaning it doesn’t heat with electricity, oil, natural gas, or even wood. It is simply heated by the sun.
Solar Hot Water
Cerridwen Farm strives to produce sustainable food with only minimal fossil fuel use, and part of this strategy is to use solar hot water. In 2009, Garrison Riegel ’06 was contracted to install solar panels on the barn roof at Cerridwen Farm. In collaboration with Mulder and environmental studies Prof. Lucas Brown, Riegel designed a system that uses solar power to provide roughly 100 gallons of hot water per day. He spent almost a week on campus, and the project turned into a hands-on seminar for GMC students in Brown’s design/build class. The Farm also has solar hot water heating one of the high-tunnel greenhouses. Not only does the hot water help to extend the growing season, but it serves as an experiment. Two identical high tunnel greenhouses were built side by side with the support of a $15,000 grant from the Windham Foundation and additional funds received through the Jensen-Hinman Family Fund. One of the high tunnels on Cerridwen Farm is equipped with a solar-thermal radiation system, which heats water and circulates it through radiant tubing running under the root zones of planting beds. The second greenhouse is heated only through passive solar energy, and serves as a controlled variable for the experiment. The main idea of the project is to find out if the farm will get significantly more production from the greenhouse equipped with solar-thermal root zone heating.
Cold Climate Heat Pump
In 2014, following a proposal from a weatherization class, GMC installed a Mitsubishi cold climate heat pump in the Two Editors Inn, to bolster a weatherization effort to offset use of the oil boiler by 40%. The effort transformed the Two Editors Inn from a standard underperforming historic building, to a model for energy efficient old buildings. Air-to-air heat pumps are becoming a more efficient way to heat indoor spaces in cold climates by using the same technology as geothermal, but without having to go underground. They work like a refrigerator in reverse. Heat pumps are a very efficient heating source, offsetting fossil fuels. They run on a small amount of electricity, which can either be clean or dirty, depending on the sources on the grid. In our case, 50% of the electricity used to power the heat pump comes from the alternative energy Cow Power program. The sustainability office hopes to work with other weatherization classes to install cold climate heat pumps in most of the outlying buildings.